[mkgmap-dev] is_in() function for point on line

Mon Jun 1 10:50:07 BST 2020

Hi Joris,

probably my ideas don't work. Your case is very special because you render the POI only when it is part of a way. The example with
entrance=main is probably not a good one as
entrance=main & is_in(building,mall,on) [...]
already works.
I've coded a better patch so that your example will also work when option --link-pois-to-ways is not used. Up to now the patch depends on that.

I do not yet see how mkgmap can avoid the generation of all useless POI without adding a lot of code to analyse the rules in the points file, but I still think about this. Problem is that we have the generated tags like mkgmap:admin_level10 or mkgmap:residential and I fear to break something that uses tricky rules with just these tags.

> Or we could work the other way around, in stead of render all poi's for all objects and not use them, the mapmaker specifies the explicit objects the poi's are needed.
Yes, might be an option. An exclude list might also work.

Gerd

________________________________________
Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Joris Bo <jorisbo at hotmail.com>
Gesendet: Montag, 1. Juni 2020 10:51
An: Development list for mkgmap
Betreff: Re: [mkgmap-dev] is_in() function for point on line

Hallo Gerd,

This works perfect ! (points - file)
mkgmap:from-node:highway = turning_circle & highway = track             [0x641a resolution 24]
mkgmap:from-node:highway = turning_circle & highway != track            [0x641b resolution 24]

Your suggestion will indeed also feature your 'entrance=main' example which is actually a very useful one to avoid cluttering
The "add-poi-to-lines" option is still usefull I think ?
For example
- to give a bicycle route a name-poi
- render a symbol for the line leisure = slipway
- render a cable car symbol for aerialway = gondola
- a warning symbol at the highway = via_ferrata
- or incline symbols at the start of steep mountain highways?

If those could be solved without rendering thousands of poi's for complex multipolygon lines that would be great of course.
Or we could work the other way around, in stead of render all poi's for all objects and not use them, the mapmaker specifies the explicit objects the poi's are needed.

Kind regards
Joris

-----Oorspronkelijk bericht-----
Van: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> Namens Gerd Petermann
Verzonden: zondag 31 mei 2020 11:38
Aan: Development list for mkgmap <mkgmap-dev at lists.mkgmap.org.uk>
Onderwerp: Re: [mkgmap-dev] is_in() function for point on line

Hi Joris,

up to now we only mentioned nodes with a highway=* tag used in ways with a highway=* tag.
I've coded a rather simple patch for that, but while I did that I wondered why this should be limited to highways.
I decided to use the prefix "mkgmap:from-node:". Tags with prefix mkgmap:  are not copied.

My understanding is that you want a function which tells you if a tagged node is used in one or more ways with a given tag.
For example, you may want to render a node with entrance=main, but only when it is the entrance to a building=mall.
This will not work, because only nodes with the tags barrier or highway are treated special.

I think it is possible to implement this as well. We probably just have to check the points rules and look for uses of "mkgmap:from-node:".
Maybe this would also allow to get rid of the computational overhead produced by the add-poi-to-lines option. The current implementation of this option is really ugly as it computes lots of points which are never used to generate any map object. Think of a complex natural=wood polygon (no other tags). If the points file doesn't contain a rule for natural=wood there is no need to generate the POIs.

I've uploaded a binary compiled with the attached patch here:
http://files.mkgmap.org.uk/download/473/mkgmap.jar

Gerd

________________________________________
Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Joris Bo <jorisbo at hotmail.com>
Gesendet: Sonntag, 31. Mai 2020 09:06
An: Development list for mkgmap
Betreff: Re: [mkgmap-dev] is_in() function for point on line

Hi Gerd

Thanks for the answer, always nice if it makes sense again. Then it was worth the testing 😊
For me that would be perfect, the number of cases this will occur is limited so that it's no problem to explicitly test against this replace value. There are probably more situations around highways where this could occur like highway = bus_stop, highway = speedcamera, and traffic signals.

Kind regards,
Joris

-----Oorspronkelijk bericht-----
Van: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> Namens Gerd Petermann
Verzonden: zaterdag 30 mei 2020 18:39
Aan: Development list for mkgmap <mkgmap-dev at lists.mkgmap.org.uk>
Onderwerp: Re: [mkgmap-dev] is_in() function for point on line

Hi Joris,
yes, it is a special case. The generated POI gets the tags from the way, so highway=turning_circle is replaced by highway=track.
The node 7131748927 appears only with the tag highway=turning_circle (and maybe the address tags)

Not sure what to do. Maybe store the replaced tag(s) with a prefix, e.g. mkgmap:replaced:highway=turning_circle in this case?

Gerd

________________________________________
Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Joris Bo <jorisbo at hotmail.com>
Gesendet: Samstag, 30. Mai 2020 18:11
An: Development list for mkgmap
Betreff: Re: [mkgmap-dev] is_in() function for point on line

Hi Gerd

Could it be possible that in this case the highway tag of the line is ignored because the point turning_circle is of type highway as well?

It's like there is a point {highway = turning_circle} on a line {highway =  track} It looks like I cannot catch it with the mkgmap:line2poitype and mkgmap:line2poi.

Somewhere else I already use
leisure = slipway & mkgmap:area2poi != true & mkgmap:line2poitype = mid  and that works fine

Kind regards,
Joris

-----Oorspronkelijk bericht-----
Van: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> Namens Gerd Petermann
Verzonden: zaterdag 30 mei 2020 17:51
Aan: Development list for mkgmap <mkgmap-dev at lists.mkgmap.org.uk>
Onderwerp: Re: [mkgmap-dev] is_in() function for point on line

Hi Joris,

is_in() only works with polygons. You can use --add-pois-to-lines, but be aware that it produces a lot of points for which you probablly don't want to add an object to the map. See the help for the details.

Gerd

________________________________________
Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Joris Bo <jorisbo at hotmail.com>
Gesendet: Samstag, 30. Mai 2020 17:40
An: Development list for mkgmap
Betreff: [mkgmap-dev] is_in() function for point on line

Hi

Does the is_in() function should also work for a point on a line in stead of in a polygon?

highway = turning_circle & is_in(highway, track, in_or_on) = true      [0x641a resolution 24]

It returns false for this situation where the turningcircle is attached to a highway = track.
(mkgmap:cache_is_in_POINT_highway_track_in_or_on=false)

Would there be another way to know if the point is attached to a highway = track rather then a for example highway = residential?
I use add-pois-to-lines, and link-pois-to-ways but as far as I can see, that doesn't give me more information.

https://www.openstreetmap.org/#map=18/49.65888/5.45845
[cid:image002.jpg at 01D636A9.5643B8A0]

Kind regards
Joris

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